Changes in activities of key enzymes of starch synthesis in the kernel of winter wheat cultivars with different gluten strength

Changes in activities of three key enzymes AGPP,SSS and SBE associated with starch synthesis were studied during grain filling stage of three winter wheat cultivars with strong,middle and weak gluten force on the condition of pond culture.The results indicated that AGPP and SBE activities of three cultivars and SSS activity of strong gluten cultivars had a single-peak curve in loam soil,their peaks appeared on 20 d after anthesis,but SSS activity of middle and weak gluten cultivars came to be a double-peak curve,the peaks appeared on 10 d and 20 d after anthesis,respectively,and the second peak was much higher than that of the first.It showed that the substrate content of starch synthesis enxymes of strong gluten cultivars in kernel was higher and starch synthesis could be more active than that of middle and weak gluten cultivars,but amylopection synthesis of middle and weak gluten cultivars in kernel could be more active than that of strong gluten cultivars.